by Sam Rutherford

The U.S. Court of Appeals for the Fifth Circuit held that geofence warrants violate the Fourth Amendment because they constitute a “general warrant.” However, the evidence acquired in the case as a result of the unlawful geofence warrant was nonetheless admissible under the good-faith exception to the exclusionary rule. The Court’s opinion on the Fourth Amendment issue is in direct opposition to one from the Fourth Circuit handed down just a month earlier, setting up a circuit split the Supreme Court will likely have to resolve at some point.

Background

Jamarr Smith, Thomas Iroko Ayodele, and Gilbert McThunel, II, were charged, tried and convicted of robbery and conspiracy to commit robbery in the U.S. District Court for the Northern District of Mississippi for robbing a Contract Route Driver with the U.S. Postal Service (“USPS”). The men were identified as suspects and ultimately convicted based on evidence obtained through a geofence warrant. As will be seen, the Government would not have been able to identify and charge these men without relying on the constitutionally repugnant mass surveillance and searches facilitated by Google.

The Crime and Initial Investigation

On February 5, 2018, Sylvester Cobbs was robbed while working as a contract driver for USPS. Cobbs picked up and delivered mail to five rural post offices in DeSoto County and Tunica County, Mississippi. The items he picked up included registered mail bags containing cash collected at the post offices from the sale of money orders and stamps.

At about 5:20 p.m., Cobbs arrived at the Lake Cormorant Post Office, which was the fourth stop along his route. Cobbs backed his mail truck up the to the rear of the post office to pick up mail bags waiting for him inside. However, before he could enter the building and collect the bags, an assailant later identified as McThunel sprayed Cobbs with pepper spray, struck him several times with a handgun, and threatened to kill him before grabbing the registered mail bags from Cobbs’ truck and fleeing. The mail bags contained $60,706 in cash. Cobbs called 911. Local police responded, but no suspects were identified or apprehended that day.

Several days later, Postal Inspector Stephen Mathews was assigned to the case. He obtained video footage from a camera across the street from the post office showing a red Hyundai and white SUV in the area during the robbery. The video showed Cobbs’ assailant exit the SUV several minutes before Cobbs arrived and hide behind the post office. The assailant appeared to be using cellphone in the video both before and after the robbery.

Mathews also spoke with a witness, Forrest Coffman, who lived across the street. Coffman had noticed the red Hyundai circling the area and asked the driver if he was lost. The driver, who Coffman described as a Black male with a reddish color goatee, said he was looking for the highway. Coffman gave him directions and then went back inside his house. A few moments later, Coffman heard police arrive at the post office and walked over to speak with them, describing the Hyundai and its driver.

Based on this evidence, Mathews assumed three individuals were involved in the robbery, but he was unable to identify any suspects. The case went cold.

Geofence Warrants: A Brief Explanation

A geofence warrant is served on a tech company (i.e., Google, Apple, Uber, Snapchat, etc.) requesting that it disclose all of its users’ location data within a given geographical area for a specified time period. As CLN has previously reported, “geofence warrants got their name, from the invisible lines of demarcation or ‘fence’ erected around a geographical space inside which users may be identified. They are also referred to as ‘reverse location search warrants’ in that, instead of identifying a known suspect and seeking to search that suspect’s property, reverse location warrants first seek to identify the suspect from an alleged location.” [CLN, Feb. 2024, pg. 1]

Although many tech companies maintain users’ location data and have received requests from law enforcement for access to it, only Google has publicly acknowledged providing the requested information to law enforcement. Google received its first geofence warrant in 2016. Since then, the requests have increased exponentially. In 2020, for example, Google received over 11,500 geofence warrants.

As explained in the February 2024 cover story of CLN, Google collects the location history of its users primarily to drive its advertising revenue. Google tracks its users in real time and with great precision, sometimes down to within just a few meters of a user’s actual location and can even identify which floor of a building a user is on. This information is stored in what Google calls its “Sensorvault.” Although location history is disabled by default, many of its apps such as the ever-popular Google Maps will not work properly unless it is enabled. Once activated, location history is by design difficult to disable. In 2018, Google estimated that one-third of its users worldwide—about 592 million daily active users—had location history enabled. Google’s location history is distinct from cell site location information because it is often considerably more precise.

Google considers location history in Sensorvault the private property of its users and therefore requires law enforcement to obtain a judicially issued warrant or other legal process prior to releasing it. Google has developed a three-step process it requires law enforcement to follow when requesting location history. First, law enforcement provides Google with the geographical and temporal parameters associated with a crime. Google then searches the millions of records stored in Sensorvault and produces a spreadsheet listing the device ID and other anonymized information for every Google user with location history enabled whose devices were in the given geographic area at the specified time. Second, law enforcement reviews the list to identify device IDs of interest, and then may request additional location history for these devices beyond the original geographic and temporal limits. Third, law enforcement may then seek disclosure of identifying information for the device IDs it has decided are relevant to its investigation at step two. This identifying information is typically the Gmail address, full name, birthdate, phone number, billing address, and even recovery email addresses associated with the device ID. Each step may be conducted pursuant to a single warrant, a separate warrant for each step of the process, or some hybrid thereof, including only a subpoena at the final step for identifying information. [CLN, Feb. 2024, pg. 1]

The Geofence Warrant and Subsequent Investigation

Nine months later, in November 2018, Mathews and fellow Postal Inspector Todd Matney learned of a new type of search warrant—called a “geofence warrant”— that they hoped could assist them identify potential suspects and witnesses in connection to the robbery.

Mathews and Matney attempted to follow Google’s three-step process. Matney, with help from Mathews and after consulting the U.S. Attorney’s Office, drafted a warrant application using several different “go-bys”—or form documents—to ensure the application included all the necessary technical language Google requires. The affidavit stated that “there is probable cause to believe that the Google accounts identified in Section I of Attachment A, associated with a particular specified location at a particular specified time, contain evidence, fruits and instrumentalities of a violation of 18 U.S.C. section 2114(a), Robbery of a U.S. Postal Service Employee.” But Section I of Attachment A did not specify any particular Google accounts. Instead, the attachment only specified coordinates around the Lake Cormorant Post Office covering approximately 98,192 square meters.

The affidavit also described the postal inspectors’ prior investigation, including a description of the two vehicles, Cobbs’ eyewitness account, the video surveillance footage, and the fact that the assailant appeared to use a cellphone both before and after the robbery. The affidavit concluded by stating that, consistent with Google’s three-step process, the inspectors would seek additional information about relevant devices “through further legal process.”

A U.S. Magistrate Judge issued the warrant on November 8, 2018, which largely tracked Google’s three-step process. The Fifth Circuit summarized its content as follows: “[A]s to Step 1, the warrant authorized an hour-long search from 5:00 p.m. to 6:00 p.m. on February 5, 2018, within a geofence covering approximately 98,192 square meters around the Lake Cormorant Post Office. As to Step 2, the warrant authorized law enforcement to obtain additional Location History for a registered device identified as relevant within ‘60 minutes plus or minus the first and last timestamp associated with the account in the initial dataset.’ However, prior to reaching Step 2, law enforcement was required to conduct ‘further legal process.’” Step 3 of the warrant authorized Google to disclose “for accounts relevant to the ongoing investigation through an analysis of provided records, … subscriber’s information … to include, subscriber’s name, email addresses, services subscribed to, last 6 months of IP history, SMS account number, and registration IP.”

In April 2019, Google provided Step 1 data from a circular area of approximately 378,278 square meters around the post office, not 98,192 square meters authorized by the warrant. Google’s search of its Sensorvault data revealed three anonymous device IDs within the specified geographic and temporal parameters. Although the initial warrant required the inspectors to obtain “further legal process” before requesting additional data from Google, Mathews and Matney decided for themselves which device IDs were relevant and requested de-anonymized information for all three devices even though only two of the device IDs registered multiple times within the geofence. On June 10, 2019, Google provided the de-anonymized information. The inspectors were able to determine that two of the three devices belonged to Smith and McThunel. The third identified account was deemed irrelevant.

Mathews and Matney used the information provided by Google to conduct further investigation related to Smith and McThunel, including sending additional non-geofence warrants to Google regarding their Google accounts, accessing their CLEAR database profiles, investigating cell tower data related to them, and sending warrants to cellphone companies for their account information. These additional warrants revealed multiple phone calls between Smith and McThunel during the time of the robbery and allowed for further geolocation of them using historical cellphone record analysis. Additionally, by searching Smith’s cellphone records and his friends on Facebook, the inspectors were able to identify Ayodele as the third suspect. The inspectors then showed Forrest Coffman photographic line-ups including all three men. Coffman identified Smith as the man he saw driving the Hyundai on the day of the robbery but was unable to identify McThunel or Ayodele.

The Prosecution and Convictions

The Government indicted Smith, McThunel, and Ayodele for conspiracy to commit robbery and the actual robbery on October 27, 2021. They filed a motion to suppress the evidence obtained from the geofence warrant. First, they argued they had a reasonable expectation of privacy in their Google location histories and that the geofence warrant used in this case was an unconstitutional general warrant. Second, they argued the geofence warrant was invalid because it was not supported by probable cause and did not describe the persons or things to be searched and seized with sufficient particularity. Third, they argued that even if the warrant was valid, Mathews and Matney failed to comply with its requirement of obtaining “further legal process” before conducting Steps 2 and 3 of the search, thus making the information provided at those steps the product of a warrantless search. The defendants contended that the good-faith exception to the exclusionary rule should not apply because these defects were so obvious the inspectors should have known the warrant was illegal and that all evidence against them should be suppressed.

The District Court held a hearing on the motion. Mathews and Matney testified consistent with the facts set forth above and further stated that their understanding of the requirement that they obtain “further legal process” at Steps 2 and 3 of the geofence warrant simply meant a demand from them to Google for the requested information. A Government expert witness, Spencer McInvaille, also testified. He educated the District Court about digital forensics and geolocation analysis, including Google location history. McInvaille stated that, given his experience in other cases, the language requiring “further legal process” in this warrant would have required additional warrants at each step of the geofence process.

The District Court denied the defendants’ motion to suppress. Following a four-day jury trial, each was convicted as charged and sentenced to between 121 and 136 months in federal prison. The defendants timely appealed.

Analysis

The Fourth Amendment guarantees that the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”

Appellate courts review the factual findings supporting a District Court’s order denying a motion to suppress evidence for clear error and its legal “conclusions regarding the sufficiency of the warrant and the constitutionality of law enforcement action de novo.” United States v. Perez, 484 F.3d 735 (5th Cir. 2007).

The Fifth Circuit addressed three related issues on appeal: (1) whether Smith, McThunel, and Ayodele had a privacy interest in their Google location history, (2) whether the geofence warrant in this case was an unconstitutional general warrant, and, if so, (3) whether the evidence was nonetheless admissible under the good-faith exception to the exclusionary rule.

Privacy Interest

“A Fourth Amendment privacy interest is infringed when the government physically intrudes on a constitutionally protected area or when the government violates a person’s ‘reasonable expectation of privacy.’” United States v. Turner, 839 F.3d 429 (5th Cir. 2016) (quoting United States v. Jones, 565 U.S. 400 (2012)). Courts employ the two-part test set forth in Justice Harlan’s concurring opinion in Katz v. United States, 389 U.S. 347 (1967), to determine whether a reasonable expectation of privacy exists in a given situation. See Jones. Relying on Carpenter v. United States, 585 U.S. 296 (2018), which the Fifth Circuit described as “arguably the most relevant Supreme Court precedent addressing law enforcement’s investigatory use of cellular consumer data,” the Court held that the defendants had a privacy interest in their Google location history.

In Carpenter, without a warrant, the Government obtained the defendant’s cell site location information (“CSLI”) that tracked his whereabouts over the course of several days. This information placed the defendant’s cellphone near four robberies, for which he was convicted. The Court of Appeals affirmed his convictions, holding that he did not have a reasonable expectation of privacy in the CSLI because cellphone users voluntarily convey this information to their cellphone carriers. The Supreme Court disagreed and reversed.

The Supreme Court has recognized that citizens have a privacy interest in their physical movements, so law enforcement must obtain a warrant before placing a GPS tracking device on their vehicles. Jones. In contrast to a GPS device on a car, CSLI tracks a person “beyond public thoroughfares and into private residences, doctor’s offices, political headquarters, and other potentially revealing locales.” Carpenter. “Accordingly, when the Government tracks the location of a cell phone, it achieves near perfect surveillance, as if it had attached an ankle monitor to the phone’s user.” Id. The Carpenter Court chose to recognize a privacy interest in CSLI in part to place “obstacles in the way of a too permeating police surveillance” and to apply Fourth Amendment protections to advancing technology capable of pinpointing “a phone’s location within 50 meters.” Id.

The Carpenter Court also ruled that CSLI is not exempt from Fourth Amendment protections under the third-party doctrine, which holds that “‘a person has no legitimate expectation of privacy in information he voluntarily turns over to third parties.’” Carpenter (quoting Smith v. Maryland, 442 U.S. 735 (1979)). It concluded this doctrine should not apply to CSLI for several reasons. First, there is a “world of difference between the limited types of personal information” in the Supreme Court’s prior third-party doctrine cases “and the exhaustive chronicle of location information casually collected by wireless carriers today.” Id. Second, to say that cellphone users “voluntarily” disclose CSLI to cellphone carriers is simply not true because having a cellphone is “indispensable to participation in modern society,” and “[a]part from disconnecting the phone from the network, there is no way to avoid leaving behind a trail of location data.” Id.

Turning to the present case, the Court had little trouble concluding that the defendants had a reasonable expectation of privacy in their Google location histories. Like CSLI, Google location history enables the Government to achieve near perfect surveillance of a citizen. In fact, Google location history “provides more precise location data than either CSLI or GPS,” the Court reasoned. Using a geofence warrant to obtain a person’s Google location history, “the government can search the pinpoint locations of over half a billion people” with “just the click of a button.” As in Carpenter, regarding CSLI, Fourth Amendment protections must be extended to Google location history to prevent “the potential for ‘permeating police surveillance’”

The Court refused to follow a Fourth Circuit decision handed down just a month earlier wherein that court held that citizens do not have a privacy interest in Google location history because the data collected using a geofence warrant is nothing more than a “record of a person’s single, brief trip” and “far less revealing than [the information] obtained in Jones [or] Carpenter.” United States v. Chatrie, 107 F.4th 319 (4th Cir. 2024). Although expressing “great respect” for the Fourth Circuit, the Court disagreed Chatrie because, while it is true that location data produced pursuant to a geofence warrant “tend to be limited temporally,” it’s also true that “such location tracking can easily follow an individual into areas normally considered some of the most private and intimate, particularly residences.” Thus, “the potential intrusiveness of even a snapshot of precise location data should not be understated,” according to the Court.

The Court also disagreed with the Chatrie Court’s conclusion that geofencing is not a search because Google users opt-in to location history. First, as in Carpenter, application of the third-party doctrine to Google location history is inappropriate because, “while cell phone data is held by private corporations, on a practical level, it is unreasonable to think of cell phone users as voluntarily assuming the risk of turning over comprehensive dossiers of their physical movements to third parties,” the Court explained. “Given the ubiquity—and necessity—in the digital age of entrusting corporations like Google, Microsoft, and Apple with highly sensitive information, the notion that users voluntarily relinquish their right to privacy and ‘assume[] the risk’ of this information being divulged to law enforcement is dubious.” Quoting Smith, supra.

Moreover, the Court questioned the voluntary nature of Google’s opt-in notices. “As anyone with a smartphone can attest, electronic opt-in processes are hardly informed and, in many instances, may not even be voluntary.” Google’s notices promise optimizations across multiple apps rather than revealing that a user’s location history will be stored digitally, “providing Google the means to access this data and share it with the government.” Furthermore, the Court stated the fact that 592 million users have opted into location tracking calls into question the voluntary nature of the process.

The Court therefore concluded that defendants have a privacy interest in their Google location histories and that postal inspectors conducted a search within the meaning of the Fourth Amendment by serving the geofence warrant on Google to obtain that data. The next issue was whether that warrant met constitutional standards.

General Warrant

“It is undeniable that general warrants are plainly unconstitutional,” the Court observed. See Standford v. Texas, 379 U.S. 476 (1965). A general warrant is one that specifies only an offense, permitting “the executing officials the decision as to which persons should be arrested and which places should be searched.” Steagald v. United States, 451 U.S. 204 (1981). The “Fourth Amendment was the founding generation’s response to the reviled ‘general warrants’ and ‘writs of assistance’ of the colonial era, which allowed British officers to rummage through homes in an unrestrained search for evidence of criminal activity.” Riley v. California, 573 U.S. 373 (2014). The Constitution combats this evil by requiring that search warrants be issued “upon probable cause … and particularly describing the place to be searched, and the persons or things to be seized.” U.S. Const. amend. IV.

Courts have long recognized that the Fourth Amendment’s particularity requirement prohibits warrants that “authorize the search of everything or everyone in sight.” Note, Geofence Warrants and the Fourth Amendment, 134 Harv. L. Rev. 2508 (2021). Thus, warrants that authorize the search of “all persons” at a crime scene survive constitutional scrutiny only if there is probable cause to believe everyone present at the time of the search was involved in the criminal activity under investigation. See Marks v. Clarke, 102 F.3d 1012 (9th Cir. 1996); Owens v. Lott, 372 F.3d 267 (4th Cir. 2004).

“Geofence warrants present the exact sort of ‘general, exploratory rummaging’ that the Fourth Amendment was designed to prevent,” the Court stated. Quoting Coolidge v. New Hampshire, 403 U.S. 443 (1971). These warrants authorize Google to search through all of its 592 million users’ location data looking for anyone who may have had a device present within the described geographical boundary at a specified time period. As the Court explained, “this search is occurring while law enforcement officials have no idea who they are looking for, or whether the search will even turn up a result. Indeed, the quintessential problem with these warrants is that they never include a specific user to be identified.” That the searches are limited by a “temporal and geographic location where any given user may turn up post-search … is constitutionally insufficient,” according to the Court.

The Government attempted to avoid this conclusion by arguing that geofence warrants are not general warrants because they are limited to specific information (location history) tied to a particular crime at a particular time and place. But the Court explained that this argument “miss[ed] the mark” because “[w]hile the results of the geofence warrant may be narrowly tailored, the search itself is not.” Instead, geofence warrants violate the Fourth Amendment’s particularity requirement because “they allow law enforcement to rummage through troves of location data from hundreds of millions of Google users without any description of the particular suspect or suspects to be found.” The Court therefore ruled that “geofence warrants are general warrants categorically prohibited by the Fourth Amendment.”

Good Faith Exception

Typically, evidence obtained in violation of the Fourth Amendment is suppressed and may not be used against a criminal defendant under the exclusionary rule. See, e.g., Wong Sun v. United States, 371 U.S. 471 (1963); Mapp v. Ohio, 367 U.S. 643 (1961). However, in United States v. Leon, 468 U.S. 897 (1984), the Supreme Court held that evidence seized by officers reasonably relying on a warrant issued by a magistrate judge should be admissible even if the warrant itself was constitutionally flawed in some way. This is known as the “good-faith” exception to the exclusionary rule.

The “good faith” exception will not apply, however, when: (1) the magistrate was misled by information in an affidavit that the affiant knew or reasonably should have known was false, (2) the magistrate wholly abandoned his judicial role, (3) the warrant affidavit is so lacking in indicia of probable cause as to render official belief in its existence unreasonable, and (4) the warrant is so facially deficient in failing to particularize the place to be searched or the things to be seized that executing officers cannot reasonably presume its validity. United States v. Woerner, 709 F.3d 527 (5th Cir. 2013) (citing Leon).

The defendants argued that their Google location histories and the evidence derived therefrom should have been suppressed under three of these exceptions. First, the postal inspectors falsely asserted that a cellphone was used during the robbery by relying on “go-bys”—or a warrant application template—to establish this fact, but defendants’ argument ignored the existence of surveillance video footage clearly showing McThunel using what appeared to be a cellphone immediately before and after he assaulted and robbed Cobbs. In light of the highly differential standard of review applied to the District Court’s factual findings and the requirement that the appellate court view evidence supporting the District Court’s ruling in favor of the prevailing party, which in this case was the Government, the defendants’ argument failed. See United States v. Pack, 612 F.3d 341 (5th Cir. 2010).

The defendants also contended that the warrant application was completely devoid of probable cause to believe they were the ones responsible for the robbery and also failed to particularly describe the persons or things to be searched (namely, them and their specific Google location histories). The Court rejected this contention. Citing United States v. McLamb, 880 F.3d 685 (4th Cir. 2018), it concluded that the postal inspectors were using “cutting edge investigative techniques” after consulting with the U.S. Attorney’s Office and other law enforcement officials concerning the appropriateness of obtaining a geofence warrant. Because the inspectors could not have known that geofence warrants violate the Fourth Amendment, the Court reasoned that there is little deterrent effect to be achieved by suppressing the unlawfully obtained evidence in this case while the cost to society would be great by allowing obviously guilty defendants to go free. See Hudson v. Michigan, 547 U.S. 586 (2006).

Conclusion

Accordingly, although the Court concluded that the geofence warrant issued in this case violated the Fourth Amendment, it nonetheless affirmed the defendants’ convictions by determining that the evidence seized pursuant to that warrant was admissible under the good-faith exception to the exclusionary rule. See: United States v. Smith, 2024 U.S. App. LEXIS 20149 (5th Cir. 2024).

Writer’s note: While the Fifth Circuit’s decision in Smith is encouraging, it by no means settles constitutional questions surrounding geofence warrants and similar investigative techniques law enforcement have more recently began to rely on. As noted above, the Fourth and Fifth Circuits reached opposite conclusions concerning the constitutionality of geofence warrants in opinions issued within just a few weeks of each other, and other courts around the country have not reached anything approaching a consensus on the issue. At least one other court agrees with the Fifth Circuit that geofence warrants are unconstitutional general warrants. People v. Meza, 90 Cal. App. 5th 520 (2d App. Dist. 2023), rev. denied 2023 Cal. LEXIS 4522 (Aug. 16, 2023); see also People v. Seymour, 536 P.3d 1260 (Colo. 2023) (holding that a “reverse-keyword warrant to obtain from Google certain user-account data” was unconstitutional, but evidence was admissible under good-faith exception).

Other courts, however, have reached conclusions similar to the Fourth Circuit in Chatrie, concluding that geofence warrants do not violate the Fourth Amendment. Price v. Superior Court, 93 Cal. App. 5th 13 (4th App. Dist. 2023), rev. denied 2023 Cal. LEXIS 5286 (Sep. 13, 2023); Wells v. State, 675 S.W.3d 814 (Tex. App. 2023), rev. granted In re Wells, 2024 Tex. Crim. App. LEXIS 58 (Tex. Crim. App., Jan. 24, 2024); State v. Contreras-Sanchez, 5 N.W.3d 151 (Minn. Ct. App. 2024), rev. granted 2024 Minn. LEXIS 280 (Minn. May 29, 2024); Tomanek v. State, 314 A.3d 750 (Md. App. 2024); State v. Shields, 2024-Ohio-2317 (Ct. App.). Until the U.S. Supreme Court addresses this issue, the constitutional validity of geofence warrants remains uncertain.   

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